This is a sort of follow up to Coaster's bulkhead foam replacement. Sometime back, can't find the post, it was mentioned that there had been a Volvo recall/Workshop tip, that behind this insulation there was, on some cars, a hole that allowed water into the heater air box cavity. It was advised that it should be sealed. Whereabouts is this hole? The air box itself must have drains somewhere, down into the A posts has been mentioned I think, and these must be prone to getting blocked with dirt, leaves etc. Where are the drains and how can you check them for blockages? The pic attached is from a Mike Brace thread on a potential restoration and shows the air box cut open, I hope he doesn't mind me using it. It shows a large hole in the inner panel. Can't think what would be routed through or fitted here except a large bore drain pipe. This looks to be nicely positioned to cause the very common wet fuse box if whatever is in this hole isn't sealing properly. Comments welcome and I'm sure those with the fuse box problem would appreciate a potential cure, if windscreen seal leaks have been ruled out.